Skripal was arrested in December 2004 by Russian authorities after he was accused of sharing state secrets with the UK's Secret Intelligence Service MI6

Moment Russian double agent Sergei Skripal is arrested in 2004

Mr Puttock added: "He looked foreign but other than that, no, he didn't look like a spy.

"He never really looked smart, he looked very casual, he stood out because of that, it's hard to remember anything special about him."

Foreign Secretary Boris Johnson today threatened to pull officials out of the World Cup if Russia was found to behind the suspected poisoning.

Bojo told MPs this afternoon it was "very difficult to imagine that UK representation to [the World Cup] could go ahead in the normal way".

Skripal was regarded as a traitor in Russia where he was jailed for 13 years in 2006.

The 66-year-old was accused of working for MI6 over several years, in particular disclosing the names of several dozen Russian agents working in Europe.

He was sentenced to 13 years in a high-security prison in August 2006, before being freed in a 2010 deal which saw 10 Russian sleeper agents expelled from the US.

Skripal retired from military intelligence, often known by its Russian-language acronym GRU, in 1999.

He went on to work at the Foreign Ministry until 2003 before becoming involved in business.

He was arrested in 2004 in Moscow and admitted he was recruited by British intelligence in 1995 and had provided information about GRU agents in Europe, for which he was paid more than £72,000 ($100,000).